title: Differential effects of rat pregnancy on uterine and lung atrial natriuretic factor receptors.
abstract: We investigated if the refractoriness to the tocolytic effects of atrial natriuretic factor (ANF) during rat pregnancy is due to a downregulation of one or both guanylyl cyclase (GC)-coupled GC-A and GC-B ANF receptors; lungs were used as controls. Uteri and lungs of virgin, pregnant (days 7, 16, and 21), and day 2 postpartum rats expressed mRNAs for GC-A and GC-B as well as GC-uncoupled ANF-C receptors. GC-B receptor protein was more abundant than GC-A in uteri; the reverse was the case in lungs. Pregnancy decreased uterine mRNAs and proteins for GC-A and GC-B receptors as well as the effects of ANF and C-type natriuretic peptide (CNP) on uterine GC activity; lung ANF receptors and effects of ANF and CNP on lung GC activity were not modulated by pregnancy. It is concluded that pregnancy induces organ-specific modulation of ANF receptors and a downregulation of ANF-GC receptors would minimize interference with uterine motility during pregnancy.
authors.affiliation: Department of Physiology, McGill University, Montreal, Quebec, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Vaillancourt
authors.forename: S
authors.initials: S
authors.lastname: Omer
authors.forename: X F
authors.initials: XF
authors.lastname: Deng
authors.forename: S
authors.initials: S
authors.lastname: Mulay
authors.forename: D R
authors.initials: DR
authors.lastname: Varma
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology; D015536:Down-Regulation; D005260:Female; D006162:Guanylate Cyclase / Q000378:metabolism*; D008168:Lung / Q000378:metabolism*; D008297:Male; D020098:Natriuretic Peptide, C-Type; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D011506:Proteins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017461:Receptors, Atrial Natriuretic Factor / Q000096:biosynthesis*; D014599:Uterus / Q000187:drug effects / Q000378:metabolism*
chemical_list: D011506:Proteins; C472610:atrial natriuretic peptide, rat; D020098:Natriuretic Peptide, C-Type; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor